Technical Field
The present invention relates to a semiconductor apparatus and a radio communication apparatus. For example, the present invention relates to a semiconductor apparatus and a radio communication apparatus that perform calibration for suppressing the second harmonic.
Background Art
In recent years, the demand for computer devices using wireless communication such as Bluetooth is increasing. Further, in order to be mounted on wearable devices, a radio circuit is required to have a single-chip configuration. Accordingly, the radio circuit has been increasingly mounted on a semiconductor apparatus, e.g., as a microcomputer or by the SoC (System on a Chip).
A radio circuit mounted on a semiconductor apparatus structures a radio apparatus by being connected to a chip resistor and a chip inductor which are provided on a substrate along with the semiconductor apparatus. With such a radio apparatus, the power of a transmission signal is amplified and transmitted from an antenna as a radio signal. Here, a class-D amplifier used to amplify the transmission signal uses pulse width modulation or pulse density modulation. Then, when the power of the transmission signal is amplified at a switching circuit, harmonics are generated.
Patent Literature 1 discloses a technique for suppressing such harmonics. According to Patent Literature 1, by allowing the amplified transmission signal to pass through an LPF (Low Pass Filter), harmonics whose frequencies are higher than the transmission signal are suppressed.